I am in the process of redesigning my Raspberry Pi based Aeroponic controller. In my new system, I am using Arduino. This time, I decided to use Bluetooth instead of WiFi to communicate between my mobile app and Arduino controller. Later I will write another post explaining about this new design. In this post I will explain how to communicate to Arduino via Bluetooth.

Arduino Bluetooth connection

I bought a Bluetooth module from Ebay, it’s a very low-cost module. The connection is pretty simple. See the connection below. I am using Arduino Nano in my new design.

Connection Details

Nano VCC to BT VCC

Nano GND to BT GND

Nano RXD to BT TXD

Nano TXD to BT RXD

In my sketch I used Softserial and I assign D2 and D3 as RXD and TXD respectively.

I haven’t used the EN and KEY pin in the Bluetooth module. You might want to use EN pin if you want to enter into AT mode to issue any commands to BT module.